Scroll Buttons

by Sourabh Singh Rathore

HTML

<div id="parent">
    <div class="contentBlock">1</div>
    <div class="contentBlock">2</div>
    <div class="contentBlock">3</div>
    <div class="contentBlock">4</div>
    <div class="contentBlock">5</div>
</div>
<span id="panLeft" class="panner" data-scroll-modifier='-1'>Left</span>

<span id="panRight" class="panner" data-scroll-modifier='1'>Right</span>

CSS

#parent {
    width:6000px;
}
.contentBlock {
    font-size:10em;
    text-align:center;
    line-height:400px;
    height:400px;
    width:500px;
    margin:10px;
    border:1px solid black;
    float:left;
}
.panner {
    border:1px solid black;
    display:block;
    position:fixed;
    width:50px;
    height:50px;
    top:45%;
}
.active{
    color:red;
}
#panLeft {
    left:0px;
}
#panRight {
    right:0px;
}

JavaScript

(function () {

    var scrollHandle = 0,
        scrollStep = 5,
        parent = $(window);

    //Start the scrolling process
    $(".panner").on("mousedown", function () {
        var data = $(this).data('scrollModifier'),
            direction = parseInt(data, 10);        
        
        $(this).addClass('active');
        
        startScrolling(direction, scrollStep);
    });

    //Kill the scrolling
    $(".panner").on("mouseup", function () {
        stopScrolling();
        $(this).removeClass('active');
    });

    //Actual handling of the scrolling
    function startScrolling(modifier, step) {
        if (scrollHandle === 0) {
            scrollHandle = setInterval(function () {
                var newOffset = parent.scrollLeft() + (scrollStep * modifier);
                
                parent.scrollLeft(newOffset);
            }, 10);
        }
    }

    function stopScrolling() {
        clearInterval(scrollHandle);
        scrollHandle = 0;
    }

}());